Tunnel construction method

ABSTRACT

A method of constructing tunnels wherein a tunnel is excavated, braced and lined. The invention contemplates that as excavation of the tunnel proceeds load-carrying internal elements are installed within the tunnel, and expandable body members are arranged between the tunnel wall and the surfaces of the internal elements confronting the tunnel wall. These expandable body members are then brought to bear against the tunnel wall and the internal elements in order to form a pressure- or forcetransmitting support.

Heierli et al.

[ 1 Aug.'7, 1973 TUNNEL CONSTRUCTION METHOD 9/1951 Kieser 61/45 R 3,131,541 51964 G th' ..6145 R [76] Inventors: Werner HeIerh, Culmannstrasse 56, 3334.162 8;]967 r gf al. R lunch, Rudolf Amberg, 3,396,545 8/1968 Lamberton 61/45 R Churfirstenstrasse 1056, g 3,492,823 2/1970 Lamberton 61/35 both of Switzerland 3,524,320 8/1970 Turzillo 61/45 R [22] Flled: June 1971 Primary Examiner-Dennis L. Taylor [21] App]. No.: 148,790 Attorney-Ostrolenk, Faber, Gerb & Soffen [30] Foreign Application Priority Data [57] ABSTRACT J ne 12' 1970 Swimfland 8940/70 A method of constructing tunnels wherein a tunnel is excavated, braced and lined. The invention contem- 1521 us. (:1. 61/42, 61/45 R plates that 89 excavation of the tunnel Proceeds load- 5 1 1 n 5 00 50 5 5 carrying internal elements are installed within the tun- [58] Field 61 Search 61/45 R, 42, 4s 1, and expandable y members are arranged 51 35 33 tween the tunnel wall and the surfaces of the internal elements confronting the tunnel wall. These expand- 5 1 References m able body members are then brought to bear against UNITED STATES PATENTS the tunnel wall and the internal elements in order to 3,509,725 5 1970 Schnabel 61/45 R form a pressure' or force'transmmmg support 2,328,779 9/1943 Bonnell 61/45 R 8 Claims, 4 Drawing Figures I m A I. 0 4 I n a U l o a I v 0 J I M f '9 1 Y a 0 ,0 N I i f, t 0 i 0 \t\ I a? a 5L A q I) u e t 9/ PATENTED W3 7 INVENTORS WERNER HE] ERLI BY QUDOLF QMBERG OStrQIenk, l osencebbi'sorren QTTORNEYS l TUNNEL CONSTRUCTION METHOD BACKGROUND OF THE INVENTION This invention broadly relates to the construction field, and, more specifically, is directed to a new and improved method of constructing tunnels, wherein the tunnel is excavated and driven ahead in conventional manner, and the tunnel is continuously braced and lined.

Conventional tunnel construction techniques used at the present time require provisional bracing of the tunnel wall, whether such be formed of rock or loose stones, directly after excavation. The bracing of the walls of the tunnel can be accomplished, for instance, by using reinforced anchors, injection concrete, and similar construction techniques. Thereafter, dewatering or draining of the tunnel is performed, and finally load-carrying internal elements, for instanced so-called tubbings or casings, are installed. Concrete is then filled into the gap between the tunnel wall and the outside surface of the interal elements. Naturally, measures must be taken to ensure for pressureless withdrawal of the water.

This prior art tunnel work technique is extremely time-consuming and therefore, of course, also correspondingly expensive.

SUMMARY OF THE INVENTION The tunnel building industry therefore is still in need of a tunnel construction technique which is not associated with the aforementioned drawbacks of the abovedescribed prior art procedures. Hence, a primary object of the instant invention is to provide a novel method of building tunnels which satisfies the existing need in the art and is not associated with the aforementioned drawbacks.

Another and more specific object of the instant invention relates to a novel method of building tunnels in a much simpler and faster manner, also reducing the cost of the construction work.

Still a further significant object of the present invention relates to a novel tunnel work construction technique wherein load-carrying internal elements are installed in the tunnel as it isexcavated, and for the purpose of providing a pressure transmitting support inflatable or expandable body members are disposed between and in contact with the tunnel wall and the confronting surfaces of the internal elements.

Yet a further significant object of the present invention relates to a novel method of shoring-up a tunnel wall during excavation in a much simpler and more rapid and economical fashion than was heretofore possible when employing conventional tunnel construction techniques, while still allowing for tunnel drainage in a very simple and efficient manner.

Now the method of the invention which fulfills the above-mentioned objectives, as well as others which willbe more apparent as the description proceeds, and especially affords a considerable simplification and reduction in the expense of tunnel construction work, contemplates that load-carrying internal elements are installed in the tunnel as it is continuously excavated. Between the tunnel wall and the surfaces of the internal elements confronting such tunnel well there are placed inflatable or expandable body members, and for the purpose of providing a pressure-transmitting support these body members are placed into bearing contact with the tunnel wall and the internal elements.

It is particularly advantageous to employ inflatable or expandable sleeves formed of a felxible material as the body members which are then placed between the tunnel wall and the internal elements. In order to provide a provisional support for the tunnel these sleeves are expanded or inflated, and thereafter such sleeves are filled with a hardenable material, as will be more fully explained shortly.

By resorting to the use of the method of the invention it is possible to immediately brace or shore-up the tunnel after it has been excavated, and specifically by installing load-carrying internal elements, for instance the tubbings or casings, andthen by expanding the intermediate body members described above it is possible to provide a pressure-transmitting support between the tunnel wall and the internal elements. This support initially can be formed provisionally, for instance by expanding or inflating the sleeves. The permanent support can then be provided by filling the sleeves with the hardenable material, for instance fine concrete or cement mortar, just to mention a few possibilities. These intermediate body members, located between the internal elements and the tunnel wall, especially if designed as expandable sleeves formed of flexible material, have the tendency of extraordinarily accommodating themselves to possible irregularities at the tunnel wall. Channels or troughs automatically appear between successive juxtapositioned expanded or inflated intermediate bodies, these channels or troughs enabling the pressureless withdrawal of water into the canalization or sewer system.

BRIEF DESCRIPTION OF THE DRAWING The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawing wherein:

FIG. I is a schematic cross-sectional view through a tunnel structure formed in accordance with the inventive method;

FIG. 2 is a sectional view through a tunnel wall which has been lined, and taken substantially along the line II-Il of FIG. 1;

FIG. 3 is a modified showing in horizontal crosssectional view of a tunnel wall, similar to the sectional view of FIG. 2; and

FIG. s is a fragmentary transverse sectional view of a tunnel, depicting filling of the hardenable filler material into the expandable sleeve members which have been inflated by air.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, in connection therewith there will be described the inventive method of building tunnel structures which provide suitable simplification and economy over the heretofore discussed prior art techniques. Now referring initially to FIG. I,

. there is shown a cross-sectional view of a tunnel structure wherein the tunnel 11 which has just been excavated from rock or stone for instance, has been lined with load-bearing internal elements 2 and by intermediately disposing between the wall of the tunnel I and these internal elements 2 inflatable or expandable body members 3 the tunnel wall has been positively braced.

The tunnel structure is built in such a way that initially the actual tunnel 1 is excavated or broken out, and then as excavation proceeds the load-supporting or load-bearing internal elements 2 are installed, and between the wall of the tunnel 1 and the outside surface of these load-supporting elements 2 there are placed the expandable sleeve members 3 formed of any suitable flexible material. The invention contemplates fixedly attaching the expandable sleeve members 3 to the pre-fabricated internal elements 2 at the outside surface thereof, namely the surface intended to confront the tunnel wall, prior to the time that these internal elements 2 are actually mounted into the tunnel. The sleeve members 3 are then inflated with compressed air, for instance at a pressure of4 atmospheres, in order to attain in this manner a provisional shoringup or bracing of the tunnel upon the load-bearing elements 2. Owing to the flexibility of the sleeves 3 such are capable of readily accommodating themselves to any existing irregularities of the tunnel wall, in other words when the expandable sleeves are inflated they can snugly bear against the wall of the tunnel.

in FIGS. 2 and 3 there have been shown respective horizontal sectional views through a tunnel wall 1 which has been lined and supported in the abovedescribed manner. At each internal element 2 there can be arranged one or more of the aforedescribed sleeve members 3. Thus, for instance, with the arrangement of FIG. 2 one such sleeve member 3 is provided for each internal element 2, while in the arrangement of PK 3 two or more such sleeve members 3 can be provided for each internal element 2. Depending upon the material from which the sleeve members 3 are formed such can be additionally covered with a suitable protective layer or protective foil.

FIG. 4 illustrates the manner in which the sleeve members 3 which have initially been filled with air can be subsequently filled with a hardenable material mass, for instance fine concrete or cement mortar, through the agency of a suitable connection 4. It is advantageous if the hardenable filling is introduced into the sleeve members 3 from below towards the top thereof in order to achieve a complete filling'of the interior of these sleeve members. The hardenable filler is pumped from a supply container 5 into the sleeves 3, the connection or filling studs 4 extending, for instance, through a bore or opening of the corresponding internal element into the interior of the tunnel tubbing. At the upper end of the sleeve member 3 there is located a valve 6 which is advantageously adjustable, and by means of which the intially introduced air can escape as the filling of such sleeve member with hardenable material proceeds, for instance while maintaining an adjustable pressure. The valve 6 can also simultaneously function as a control for filling of the sleeve member 3, in other words as an overflow control.

Naturally, it would also be possible to flowcommunicate a number of sleeve members with one another, so that they could be filled while using a single inlet with air or the hardenable material.

Instead of having the expandable sleeve members extend in the direction of the height of the tunnel, they could also run in the direction of the length of the tunnel. It is not critical to the concepts of the invention in which direction the sleeve members extend. Basically, it is also conceivable to use, instead of expandable sleeve members or hoses, different types of fillable body elements which can be, for instance, expanded and strengthened by a chemical technique.

An advantage of the above-described method resides in the fact that after installation of the internal support or internal lining which is required in each instance, it is possible to very rapidly achieve a provisional support and sealing of the tunnel by expanding the fillable body members, and which when using these expandable or inflatable sleeves can be attained in a very simple manner, and by filling such with the hardenable material these sleeves can provide a final support and scaling for the tunnel.

When using the proposed expandable or inflatable sleeves there are formed the channels or troughs, schematically indicated by reference numeral 8 in FIGS. 2 and 3, required for the pressureless withdrawal of the water, so that in this regard it is not necessary to resort to any further special measures. The shape of the sleeves as well as their spacing from one another can be conveniently chosen in accordance with the encountered requirements.

While there is shown and described present preferred emobdiments of the invention, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims.

What is claimed is:

l. A method of building a tunnel, which comprises the steps of:

a. excavating a tunnel and as excavation proceeds installing load-bearing internal elements at the tunnel;

b. arranging expandable body members comprised of expandable sleeves formed of flexible material between the wall of the tunnel and the surface of the internal elements facing such tunnel wall; and

c. bringing the body members into bearing contact against the tunnel wall and the internal elements for the purpose of forming a pressure-transmitting support through inflating the expandable sleeves in order to provide a provisional support, and thereafter filling such sleeves with a hardenable material.

2. The method as defined in claim 1, including the step of fixing the expandable sleeves to the rear surface of the internal elements intended to confront the tunnel wall prior to the time that the internal elements are installed in the tunnel.

3. The method as defined in claim 1, including the step of at least partially evacuating the expandable sleeves prior to filling such with the hardenable material.

4. The method as defined in claim 1, wherein the expandable sleeves are initially inflated with air, and further wherein a predetermined pressure is maintained in such sleeves until hardening of the filled material.

5. The method as defined in claim 1, including the step of using as the hardenable material fine concrete.

6. The method as defined in claim 1. including the step of using as the hardenable material cement mortar.

7. The method as defined in claim I, wherein the expandable sleeves are filled with the hardenable material from the bottom towards the top thereof.

8. The method as defined in claim 1, wherein an elastically or plastically deformable filling material is used for providing a flexible support.

1 i I! i i 

1. A method of building a tunnel, which comprises the steps of: a. excavating a tunnel and as excavation proceeds installing load-bearing internal elements at the tunnel; b. arranging expandable body members comprised of expandable sleeves formed of flexible material between the wall of the tunnel and the surface of the internal elements facing such tunnel wall; and c. bringing the body members into bearing contact against the tunnel wall and the internal elements for the purpose of forming a pressure-transmitting support through inflating the expandable sleeves in order to provide a provisional support, and thereafter filling such sleeves with a hardenable material.
 2. The method as defined in claim 1, including the step of fixing the expandable sleeves to the rear surface of the internal elements intended to confront the tunnel wall prior to the time that the internal elements are installed in the tunnel.
 3. The method as defined in claim 1, including the step of at least partially evacuating the expandable sleeves prior to filling such with the hardenable material.
 4. The method as defined in claim 1, wherein the expandable sleeves are initially inflated with air, and further wherein a predetermined pressure is maintained in such sleeves until hardening of the filled material.
 5. The method as defined in claim 1, including the step of using as the hardenable material fine concrete.
 6. The method as defined in claim 1, including the step of using as the hardenable material cement mortar.
 7. The method as defined in claim 1, wherein the expandable sleeves are filled with the hardenable material from the bottom towards the top thereof.
 8. The method as defined in claim 1, wherein an elastically or plastically deformable filling material is used for providing a flexible support. 